Tick-Host Specificity

A review the various patterns of tick-host relationships are discussed in detail in order to answer the following questions : <br> 1. How, when and where did host specificity of each parasite group evolve ? <br> 2. How strict is specificity in each case ? <br> 3. Why and under what circumstances does specificity break down ? <br> The authors present several definitions which characterize the various degrees of parasitic specificity existing today between ticks and their hosts. <br> Tick-host relationships are presented in relation to life-cycle patterns and also to their appearance in the evolution of the various classes of terrestrial vertebrates. Special attention is paid to the ticks of mammals. A family tree has been set up to display the families, subfamilies and genera of ticks.